Filling grate for looms



May 10, 1966 c. E. MURRAY FILLING GRATE FOR LOOMS Filed May 6, 1964 COYT E. MURRAY ATTORNEY United States Patent 3,250,309 FILLING GRATE FOR LGGMS Coyt E. Murray, 527 N. Broad St., Gastonia, N.C. Filed May 6, 1964, Ser. No. 365,251 8 Claims. (Cl. 139-379) This invention relates to a filling grate for looms and more particularly to a filling grate of novel and economic construction which incorporates means for preventing excessive accumulations of lint on the grate.

The present invention is intended for use in a filling detecting device of the type having a pivoted fork which is adapted to be displaced by the filling yarn being pressed against the filling grate with which the present invention is concerned. Absence of a filling yarn adjacent the grate results in failure of the filling fork being displaced, which, in turn, effects the operation'of usual devices for stopping the loom or effecting a bobbin transfer.

Difiiculty has long been experienced in combating accumulation of lint in the openings of the grate element of the filling detecting device. Unless manually cleaned at frequent intervals lint collects in the openings of grates of the prior art to such an extent thatthe normally open space between the horizontally spaced vertically extending ribs of the prior art grates become clogged with lint to such an extent that, in the absence of a filling yarn, the fork will nevertheless be pivoted through engagement of its tines with the excessive accumulations of lint between the ribs of the grate, thus giving a false test for the presence of a filling yarn. In this event, the loom will continue to operate in an improper manner until the absence of a filling in the cloth is detected by the loom operator.

Prior attempts to deal with this problem have comprised efiforts to coat the surface of the grate with substances to which lint will not adhere as readily as it will to metal. Various cleaning devices for removal of accumulations of lint have also been proposed as have modifications to the filling detecting apparatus Which would not mistake excessive accumulations of lint for a filling yarn.

In all of the earlier attempts to solve the problem of excessive accumulations of lint in the filling detecting mechanism of which applicant is aware, no departure has been made from the conventional skeleton construction of the filling grate. The filling grate has consistently been formed of an open framework of metal or a metal base in which a plurality of horizontally spaced vertically extending ribs are joined at their upper and/or lower ends, leaving the medial portions of the ribs unconnected. Apparently, it has been universally and logically believed that one effective manner of combating accumulations of lint was to provide a minimum amount of structure or surface to which the lint could adhere.

Examples of the skeleton or open backed" grates of the prior art to which reference is here made may be found in Patent 2,226,280 issued December 24, 1940 to William H. Bahan, Patent 2,733,735 issued February 7, 1956 to Samuel L. Huffman, Patent 2,156,838 issued May 2, 1939 to Bennie S. Brown, Patent 2,672,895 issued March 23, 1954 to Robert M. Ingham, Jr., and Patent 2,832,376 issued April 29, 1958 to Stanley Livingstone.

As is well known to those skilled in the art, the practice of forming the filling grate with a minimum of surface area in an effort to combat accumulations of lint has caused an ancillary problem in that the attendant lightweight construction of such filling grates tends to promote fracturing of the lug connection to the loom due to the intense vibration of the looms in operation. Thus, the skeletonized or open backed grates of the prior art have not only failed to solve the problem of lint accumulation,

3,250,301: Patented May 10, 1966 but their lightweight construction has necessitated frequent replacement of the filling grates due to breakage with consequent down-time of the looms.

As recognized in Patent 2,672,895 to Ingham, it is pos-.

point of rigidity. That is, Ingham found that plastic grates formed in the conventional skeletonized form were not sufficiently rigid to withstand the intense loom vibration.

It is therefore an object of this invention to take advantage of the economies of injection molding in the formation of filling grates while at the same time producing a grate of sufiicient rigidity to withstand the loom vibrations and give long service, and wherein the preferred embodiment of the grate includes an imperforate base from which ribs project therefrom toward the filling fork, spaces being defined between the ribs for reception of the tines of the fork in the conventional manner when the filling yarn is broken. The polymeric material of the filling fork is preferably treated with an anti-static composition in order to minimize the adherence of lint on the surface of the grate.

It has been surprisingly found that the imperforate base wall of the filling grate, rather than aggravating the problem of lint accumulation, actually aids in removal of accumulations of lint in the openings between the ribs of the grate. This is apparently accomplished by the impingement of air currents, created by reciprocal move mechanism applied to a loom and embodying the grate of the present invention;

FIGURE 2 is an enlarged perspective view of the filling grate of the present invention removed from the loom and looking at the end opposite that shown in FIGURE 1;

FIGURE 3 is a horizontal sectional view taken substantially along the line 3-3 in FIGURE 2;

FIGURE 4 is an elevation view looking at the side opposite that shown in FIGURE 2.

Referring more specifically to the drawings, the numeral 10 broadly indicates a filling detecting mechanism comprising a filling fork 11 and a filling grate 12. The filling fork 11 includes tines or prongs 13 extending from head block 14 which is pivotally mounted as by pin 15 to the slide 16 in a conventional and well known manner. Attached to the block 14 at approximately right angles to the tines 13 is a loop member 20 by which the block 14 is engaged to stop the loom or replenish a bobbin in a conventional manner if the head 14 is not pivoted about pin 15 as by engagement of the tines 13 with a filling yarn extending across the grate 12.

The grate .12 is partially positioned within a groove or well 2 1 defined in loom lay 22, and fastened to the side Wall of shuttle box 2 3 as by screw 24, so as to move back and forth with respect to the filling fork 11 during operation of the loom.

As most clearly seen in FIGURES 2 and 3, the grate 12 is formed as an integral unit comprising a U-shaped body portion including end walls 25 and 26 whose proximal edges are joined by an imperforate web or base 27. A mounting lug 39 is formed integral with end wall 25, the mounting lug 30 being provided with a bore 31 through which the bolt 24 is passed tosecure the grate 12 to the lay 22.

Ribs 32 and 33 are formed integral with the base 27 and project from said base between the end walls 25 and 26. The ribs 32 and 33 are co-extensive with the end walls 25 and 26, the end walls 25, 26 and the ribs 32, 33 together defining spaces or openings 34, 35 and 36 adapted to receive the tines 13 on the filling fork L1.

The grate 12 is preferably formed from nylon or polyethylene by injection molding although the invention is not limited to the material from which the grate is fabricated nor to the manner in which the grate is formed, it being understood that the grate can be formed from any desired material and'in any desired manner Within,

the spirit of the invention. In one embodiment of the invention wherein the grate is molded from polyethylene, it has been found desirable to treat the polyethylene with an anti-static solution which would minimize the tendency of the polyethylene to attract lint. A product marketed by Arnold, Hoffman & Co., Incoroporated, 55 Canal Street, Providence, Rhode Island, under the trademark AHCOSTAT PX has been found desirable. AHCOSTAT P is a surface-active agent which at room temperature is a fairly free flowing paste of a slightly fawn color. If mass-incorporate in polyethylene, the agent migrates to the surface of the molded or extruded article, to form a hydrophilic surface layer which induces good slip characteristics in films and which, by absorption of a little moisture, reduces the tendency to acquire an electrostatic charge. The surface layer develops in six to twelve hours after processing, and, although removable by washing, reforms after a few hours, thus giving a degree of permanent anti-static protection not obtained by surface application of antistatic agents. The physical form of AHCOSTAT PX does not allow an even distribution in the plastics to be obtained by direct addition. It is therefore recommended that the agent be incorporated as a pre-dispersed master batch, either (1) as a concentrate in polyethylene itself or (2) as a powder dispersion. In each case the recommended concentration is of the order of 0.075 percent (calculated as AHCOSTAT PX on weight of polymer). The concentration may be adjusted to suit individual requirements.

A suitable concentration (12%) of AHCOSTAT PX in polyethylene can be prepared as fully described in Technical Note No. RC-4 published July 25, 1960 by Arnold, Hoffman & Co., Incorporated, 55 Canal Street, Providence, Rhode Island.

Similarly, if it is desired to form the grate 12 from nylon, polystyrene or acrylic polymers, the use of an anti-static agent marketed by Arnold, Hoffman & Co., Incorporated, 55 Canal Street, Providence, Rhode Island, under the trademark AHCOSTATIC S has been found to be desirable. This antistatic and its method of application is described in Technical Note No. RC-7 published July 25, 1960 by Arnold, Hoffman & C0., Incorporated.

The use of anti-static agents to minimize the tendency of lint and the like to adhere to the surface of the grate is helpful in combating accumulations of lint but the physical structure of the grate has been found to play at least an equal part in keeping the grate free from lint. As most clearly seen in FIGURES 2 and 3, the

end walls 25 and 26 and the base or rear wall 27 are relatively thick in transverse cross-section compared with area approximately twice that of the end wall 25 to which the lug 30 is joined.

As has been noted, the ribs 32 and 3-3 are thinner than the end walls 25 and 26 but the ribs 32 and 33 at their juncture with the base 27 are substantially thicker than their free or leading edges 32a and 33a which, together with corresponding edges of the end walls 25, 26, define the face of the grate. The thin leading edges 32a and 33a combine with the smooth surface of the ribs 32, 33 and the end walls 25, 26 and the smoothly rounded areas 40 at the juncturesof the ribs 32, 33 with the base 27 define unimpeded air passageways or channels through which air moves at sufii ciently high velocity to purge lint from the surface of the grate as the loom lay moves back and forth. The imperforate base 27 is helpful in increasing the velocity and turbulence of the air currents in that it forces the air currents to change direction within the narrow air channels as the air is forced to move around the edges of the base 27.

The face of the grate defined by the leading edges 32a and 33a of the ribs 32, 33 and the corresponding leading edges of the end walls 25, 26 is concave in transverse cross-section, i.e. the face defines a longitudinal curve which projects its upper and lower end portions beyond its medial portion as viewed in FIGURE 2. This gentle curve is beneficial in retaining the filling yarn within the confines of the grate and overcoming its tendency to drop below or rise above the grate with the consequent danger of giving a false reading to the filling fork.

It is thus seen that I have provided a grate having anti-static properties and incorporating means for cleaning and preventing accumulations of lin't, which grate may be ruggedly produced in an economic manner.

In the drawings and specification there have been set forth preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. In a filling detecting mechanism for a loom having cooperating fork and grate elements mounted for relative bodily movement toward and away from each other, said grate comprising;

(1) a generally U-shaped body portion defined by,

(a) a pair of spaced parallel end walls,

(b) a web extending between the end walls and coextensive with the proximal edges of the end walls,

(2) ribs extending from the web between the end walls in spaced parallel relation to each other and to the end walls to define air channels,

(3) said ribs and said end walls terminating in a common plane spaced from and parallel to the web to define the face of the grate,

(a) and said air channels communicating with the atmosphere at said face and at the longitudinal edges of the web between the end Walls.

2. A structure according to claim 1 wherein,

(l) the web and end walls are of a given uniform thickness,

(2) a mounting lug extends outwardlyfrom one end wall,

(a) the mounting lug being of a cross-sectional thickness approximately twice that of the body portion, and

(3) the ribs are of an average cross-sectional thickness approximating one-half that of the body portion.

,3. A structure according to claim 1 wherein the Walls defining said air channels are smooth and wherein the jun'ctures of the ribs with the Web are rounded.

4. A structure according to claim 3 wherein:

(l) the ribs are thicker at their junctures with the Web than at the face of the grate.

5. A structure according rto claim 4 wherein the web is imperforate.

6. A structure according to claim 5 wherein the fiace of the grate is concave in transverse cross-section.

7. A structure according to claim 6 wherein the grate is formed from plastic.

8. A structure according to claim 7 wherein the plastic from which the grate is formed is treated with an antistatic composition.

References Cited by the Examiner UNITED STATES PATENTS 6 Brown et al 139-379 X Squires 139-379 Rinne et al 139-378 Ingham 139-379 Huffman et a]. 139-379 Livingstone 139-379 FOREIGN PATENTS Great Britain.

DONALD W. PARKER, Primary Examiner.

J. KEE OHI, Assistant Examiner. 

1. IN A FILLING DETECTING MECHANISM FOR A LOOM HAVING COOPERATING FORK AND GRATE ELEMENTS MOUNTED FOR RELATIVE BODILY MOVEMENT TOWARD AND AWAY FROM EACH OTHER, SAID GRATE COMPRISING: (1) A GENERALLY U-SHAPED BODY PORTION DEFINED BY, (A) A PAIR OF SPACED PARALLEL END WALLS, (B) A WEB EXTENDING BETWEEN THE END WALLS AND COEXTENSIVE WITH THE PROXIMAL EDGES OF THE END WALLS, (2) RIBS EXTENDING FROM THE WEB BETWEEN THE END WALLS IN SPACED PARALLEL RELATION TO EACH OTHER AND TO THE END WALLS TO DEFINE AIR CHANNELS, (3) SAID RIBS AND SAID END WALLS TERMINATING IN A COMMON PLANE SPACED FROM AND PARALLEL TO THE WEB TO DEFINE THE FACE OF THE GRATE, (A) A SAID AIR CHANNELS COMMUNICATING WITH THE ATMOSPHERE AT SAID FACE AND AT THE LONGITUDINAL EDGES OF THE WEB BETWEEN THE END WALLS. 